The present invention relates to the manufacture of felted fibrous webs or mats formed by projecting a stream of fibers toward a moving porous support on which the fibers are interlaced into a web-like structure. Natural and synthetic fibers such as cotton, rayon, kapak, wool and wood and other textile and paper fibers are employed in forming the fibrous structure although small quantities of mineral fibers and other additives may be mixed in with the aforementioned fibers which are hereinafter called cellulosic type fibers. If desired, binders such as starch, synthetic resins and other known adhesives may be used to strengthen the structure of the web. The selected binder in liquid or dry state may be mixed with the fibers at any convenient stage in the process or the binder may be applied to the web-like structure after it is formed. The binder is preferably added before the fiber is collected on the porous support. The resin binders such as the phenolics, latices, urea-formaldehyde, melamine-formaldehyde and epoxy resins are usually cured by application of heat to set the resin. Various processes are available for forming the above described felted fibrous mats. One typical example is described in the Duval, U.S. Pat. No. 2,646,381.
A major drawback to the known processes is that the fibers are not uniformly felted in the desired random orientation and there are clots or entanglements of fibers interspersed with thin spots throughout the structure of the web. As a result, the product does not have the desired strength, loft, stretch, drape, and softness required in many commercial applications especially in those cases where only a very thin web can be employed.